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Date: Mon, 4 Nov 2002 16:37:44 -0500 (EST)
From: Alexander Viro <viro@math.psu.edu>
To: "Adam J. Richter" <adam@yggdrasil.com>
cc: tytso@mit.edu, linux-kernel@vger.kernel.org, axboe@suse.de
Subject: Re: Patch(2.5.45): Eliminate unchecked kfree(disk->random)
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On Mon, 4 Nov 2002, Adam J. Richter wrote:

> 	alloc_disk in linux-2.5.45/drivers/block/genhd.c calls
> rand_initialize_disk, which can set disk->random to NULL on kmalloc
> failure.  disk_release does a kfree(disk->random) without checking.

kfree(NULL) is guaranteed to be OK and is a very common idiom.  Talk
to Linus about that - it's a religious issue and FWIW I'm on the same
side ("free(NULL) should be allowed").  IIRC, Linus had claimed quite
a few times that change of kfree() that would break kfree(NULL) would
be considered as a bug.

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